Maxine Onsite: Estimating Dose from Chronic Atmospheric Radioactive Releases

Conference · Mon Jul 01 04:00:00 EDT 2019

OSTI ID:23005508

Morrison, Courtney ^[1]

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1. Department of Environmental Science and Biotechnology, Aiken, South Carolina (United States)

Maxine Onsite: Developed to estimate dose to individuals who are working onsite but are not site employees. Follows the methodologies discussed in US NRC Regulatory Guides 1.109 and 1.111 to determine dose from a chronic atmospheric release. Determines the dose given relative air concentrations and deposition concentrations as input. We look at four locations onsite that may be accessed by members of the public. To show compliance with the EPA and DOE public dose limit of 10 mrem/yr, determining who is a member of the public or a worker onsite is necessary. SRS has defined a member of the public for NESHAPS and DOE O 458.1. Maxine Onsite runs on Microsoft Windows Operating System through a Microsoft Excel spreadsheet. Input from the user includes parameters that are variable such as air concentrations, and fixed, such as distance to the receptor and elemental iodine fraction. Maxine Onsite was developed from Maxine which is a program meant to calculate dose to the MEI via three pathways, external, inhalation, and ingestion. Maxine Onsite is meant for looking at the exposure through the external and inhalation pathways only, no local food production onsite. The ways that Maxine Onsite is used to calculate the dose to the MEI includes the following: - Determining the respective air concentration values at each location using distances from the release stack; - Breathing rates for the MEI; - Determining the amount of time the MEI is outside; - Determining the plume travel time. The following relative air and ground deposition values for proper execution of the spreadsheet come from MAXDOSE-SR and are needed to accurately determine the dose to the MEI: relative air concentration, relative air concentration decayed by 2.26 days, relative air concentration decayed and depleted for 8 days, and relative deposition. Test cases were designed, developed, and executed to determine the accuracy of Maxine Onsite, which were verified additionally through hand calculations. Several changes were made for testing, including varying air concentrations, distances, breathing rates, and shielding factors. Each test case was then verified through hand calculations to assure the accuracy of the calculated doses. The results from the test cases, as well as the default parameters, can be used for benchmarking Maxine Onsite in the future. Maxine Onsite performs as expected and produces correct and accurate results at each of the different locations onsite (TRL, B-Area Barracks, SRELCC, and Gunsite 51) for varying test cases. The input required by the user is minimal and includes the results of the dose to the MEI on the first page for ease of access. Future plans for Maxine Onsite include adding in the ingestion pathway and adding in atmospheric dispersion estimates to the spreadsheet.

• Research Organization: WM Symposia, Inc., PO Box 27646, 85285-7646 Tempe, AZ (United States)
• OSTI ID: 23005508
• Report Number(s): INIS-US--21-WM-P30
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
61 RADIATION PROTECTION AND DOSIMETRY
BENCHMARKS
DEPOSITION
DOSE LIMITS
DOSIMETRY
ECOLOGICAL CONCENTRATION
FISSION PRODUCT RELEASE
INGESTION
INHALATION
IODINE
PLUMES
RADIATION DOSES
RADIATION PROTECTION
RECEPTORS
SHIELDING
TESTING
US EPA
US NRC